We have read with interest the article published by Pérez et al., we really appreciate their interesting comments and would like to qualify some points. With the except of the clinical practice, currently there is no recommendation based on scientific evidence about the use of apheresis in the treatment of ulcerative colitis (UC), and even less in Crohn's disease (CD). However, the results obtained in the case of Pérez et al. in relation to systemic inflammation and pulmonary clinical improvement are very interesting from a pathophysiological and clinical point of view.